In general, a heat exchanger for cooling air in a vehicular air conditioning apparatus has tubes, a first tank, a second tank and fins. The first tank is coupled to first ends of the tubes for introducing an internal fluid, such as a refrigerant, into the tubes. The second tank is coupled to second ends of the tubes for collecting the internal fluid from the tubes. The internal fluid is evaporated while flowing through the tubes by receiving heat from an external fluid flowing outside of the tubes, such as air. The fins are joined to outer surfaces of the tubes for improving efficiency of heat exchange between the internal fluid and the external fluid. Such a heat exchanger is, for example, described in Japanese Unexamined Patent Application Publication No. 2000-179988.
For example, a heat exchanger has a resin coating. In forming the resin coating in a manufacturing process, the first and second tanks, the tubes and the fins are assembled first, and then the assembled heat exchanger is immersed in a liquid resin tank. Next, the heat exchanger is removed from the liquid resin tank. In this condition, surplus liquid resin remains on the outer surface, such as the outer surfaces of the fins.
Thereafter, air is applied to the heat exchanger by a blower for removing the surplus liquid resin, thereby forming the resin coating having uniform thickness. In applying the air by the blower, if the velocity of the air is high, the surplus liquid resin is likely to be splashed due to air pressure when a flow direction of the air is changed by colliding with the heat exchanger.
If the splashed liquid resin sticks to the blower and is cured on the blower, the blower will be broken. Also, the splashed liquid resin may stick to surrounding walls. If the resin comes off from the surrounding walls, it may stick to the heat exchanger.